What is Medicare’s Home Infusion Therapy benefit?

It is a Part B benefit, fully phased in on January 1, 2021, that pays for the professional services associated with home administration of certain IV drugs through an external infusion pump. The professional services include nursing visits, patient and caregiver education, remote monitoring, and care coordination on days when infusion is administered. The drug itself and most supplies are covered separately under the Part B DME (durable medical equipment) benefit. The two together replaced an earlier, narrower coverage framework and were designed to support outpatient parenteral therapy at home rather than in a SNF or hospital.

What drugs are covered?

Drugs included on the Medicare home infusion therapy transitional and permanent drug lists. These cover the most common categories: long-course IV antibiotics (vancomycin, ceftriaxone, daptomycin, ertapenem and others) for osteomyelitis, endocarditis, complicated cellulitis, and prosthetic joint infections; immune globulin (IVIG) for autoimmune and immunodeficiency indications; certain chemotherapy maintenance and supportive drugs; antifungal therapy; selected biologic and rare disease drugs. Parenteral nutrition (TPN) is covered under a separate longstanding Part B nutrition benefit, not Home Infusion Therapy.

How is home infusion different from Part D drugs?

Part D covers oral and self-administered drugs through stand-alone Part D plans or Medicare Advantage Part D. Home Infusion Therapy is Part B; it covers drugs delivered by external pump that are not self-administered in the Part D sense. Some IV drugs originally covered under Part D for in-home use moved into Part B Home Infusion Therapy when the benefit was created. The practical difference for the senior is that home infusion drugs go through the Part B benefit (with Part B coinsurance) and require a Medicare-enrolled home infusion supplier, not a Part D pharmacy.

What about Part A home health for IV care?

Part A home health is a separate benefit. When a senior is homebound and has a skilled need, the home health agency can administer IV therapy as part of the broader home health episode. This often applies when IV therapy is one component of a larger care plan that also includes wound care, physical therapy, or other skilled services. Home Infusion Therapy under Part B exists for situations where IV therapy is the primary need and a home health episode is not appropriate or efficient.

Does home infusion require prior authorization?

Many home infusion drugs and the pump itself require prior authorization, especially through Medicare Advantage plans. Original Medicare typically requires documentation of medical necessity rather than formal prior authorization for the most common indications. The home infusion provider (a specialized pharmacy and nursing supplier) handles most of the paperwork. The treating physician needs to document the diagnosis, the rationale for IV therapy versus oral alternatives, the planned duration, and the safety of home administration.

Who decides if home is safe for the infusion?

The treating physician, the home infusion pharmacy team (which includes pharmacists and nurses experienced in OPAT and infusion safety), and the family. Common safety considerations: a functioning IV access device (usually a PICC line or midline placed before discharge), a caregiver present at least during initial doses, no untreated substance use that would compromise line safety, a home environment that supports clean medication handling, and reachable emergency services if a reaction occurs. The Infectious Diseases Society of America OPAT guidelines describe candidate selection criteria for outpatient parenteral antibiotics specifically.

What does a typical home infusion day look like?

On the first day, a home infusion nurse arrives, inspects the IV access, teaches the patient and family how the pump works, demonstrates the connection and disconnection procedure, reviews emergency signs (fever, swelling at the site, breathing changes), and stays for the initial infusion. On subsequent days the patient or family typically connects the pump under prior training. The nurse returns periodically (often weekly) for line care, blood draws if monitoring is needed (like vancomycin troughs for antibiotics), and reassessment. The infusion itself takes minutes to several hours depending on the drug.

Home IV infusion: the Medicare benefit explained

Why home IV infusion is the question it is

For decades, a senior who needed two, four, or six weeks of intravenous antibiotics for a serious infection had one realistic option: a skilled nursing facility, paid out of the limited Part A SNF benefit. That model worked, sometimes, but it was inefficient, expensive, and removed the patient from home for weeks when they did not need 24-hour nursing for any other reason. The Medicare Home Infusion Therapy benefit, which finished its phase-in on January 1, 2021, was built to fix this.

Home infusion is now the default for many indications that previously kept seniors in facilities: long-course IV antibiotics for osteomyelitis or endocarditis, immune globulin therapy for primary immunodeficiency and certain autoimmune conditions, parenteral nutrition for severe gastrointestinal disease, and various chemotherapy maintenance and biologic infusions. Understanding which Medicare part covers what is the difference between a smooth transition home and weeks of confusion and balance billing.

What the Home Infusion Therapy benefit actually pays for

The Part B Home Infusion Therapy benefit pays for the professional services associated with home infusion on the days when infusion is administered. Specifically:

Nurse visits for teaching, monitoring, and care coordination
Pharmacist and care team consultation
Remote monitoring as part of the care plan
Care coordination with the prescribing physician

The drug itself and most supplies are covered separately under the Part B DME (durable medical equipment) benefit. The DME piece includes:

The external infusion pump
Tubing, catheters, dressings, and other supplies needed to deliver the drug
The drug, when on the Medicare home infusion drug list

Together, these two pieces (HIT professional services + DME drug and supplies) replace what used to be a fragmented and gap-prone billing arrangement before 2021.

The drugs on the list

Medicare maintains a transitional and permanent home infusion drug list. The list covers the most clinically common home infusion needs:

Long-course IV antibiotics. Vancomycin, ceftriaxone, daptomycin, ertapenem, cefepime, ampicillin-sulbactam, and others. These are the workhorses of outpatient parenteral antimicrobial therapy (OPAT) for osteomyelitis (especially diabetic foot infections and vertebral osteomyelitis), prosthetic joint infections, endocarditis after initial inpatient stabilization, and complicated soft tissue infections.

Immune globulin (IVIG). For primary immunodeficiency, chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy, certain dermatologic and rheumatologic indications, and selected hematologic conditions. Many patients are stable on chronic IVIG and infuse every three or four weeks at home.

Antifungals. Selected IV antifungal drugs for systemic fungal infections.

Chemotherapy maintenance and supportive drugs. Specific regimens are covered.

Selected biologic and rare disease drugs. Several specialty drugs, particularly those for rare metabolic and immune-mediated conditions.

Parenteral nutrition (TPN) is covered under a separate longstanding Part B nutrition benefit, not Home Infusion Therapy. For seniors who cannot maintain adequate nutrition orally, home TPN is a major California outpatient program and is typically managed by specialty nutrition support clinics.

Part A, Part B, Part D: which one is paying

Medicare’s payment structure for infusion is more complicated than most patients realize, and clarifying it upfront prevents billing surprises later.

Part A home health. When IV therapy is one component of a home health episode (the senior also needs wound care, physical therapy, or other skilled services), the IV therapy is covered as part of the home health benefit. The home health agency provides the nurse. The drug and pump may still bill separately.

Part B Home Infusion Therapy. When IV therapy is the primary reason for ongoing care, with no broader home health need, Part B Home Infusion Therapy is the relevant benefit. The home infusion provider (a specialty pharmacy and nursing supplier) is the primary contact, not a traditional home health agency.

Part B DME. The drug and pump for home infusion drugs on the Medicare list. The home infusion supplier coordinates the DME side.

Part D. Oral and self-administered medications, plus certain self-injected drugs. Most home infusion drugs are not Part D drugs.

The senior’s Part B coinsurance applies to the Home Infusion Therapy services and the DME drug. A Medigap policy or a Medicare Advantage plan changes how those costs are paid. Medi-Cal as secondary coverage often picks up the cost-sharing for dual-eligible members.

What the home infusion provider does

A Medicare-enrolled home infusion supplier is more than a delivery service. The supplier typically:

Receives the order from the discharging hospital or treating physician
Verifies benefits and coordinates prior authorization where required
Pharmacists review the drug, dose, IV access type, and any drug interactions
Compounds the drug under sterile conditions and delivers it to the home with appropriate cold chain handling
Sends a trained infusion nurse for the first dose, patient teaching, and ongoing visits
Provides 24/7 clinical phone support during the therapy course
Coordinates lab monitoring (vancomycin troughs, IVIG pre-medications, liver and kidney function as indicated)
Documents the course and reports back to the treating physician

Several large national home infusion providers operate across California, alongside hospital-affiliated and independent regional providers. The discharging team typically selects the supplier based on insurance contract and geographic coverage.

The clinical safety frame for home OPAT

The Infectious Diseases Society of America publishes guidelines for outpatient parenteral antimicrobial therapy (OPAT). The candidate criteria are useful for any home IV antibiotic course:

Stable on therapy after initial inpatient observation (typically 48 to 72 hours)
Reliable IV access, usually a PICC line or midline placed before discharge
Caregiver presence for at least the first several doses, and ideally throughout the course
No active substance use that would compromise line safety
A home environment that supports clean medication handling and refrigeration where needed
Reachable emergency services if a reaction occurs
A plan for lab monitoring and follow-up with the treating physician or infectious disease consultant

For seniors with cognitive impairment, the model leans more heavily on a competent family caregiver or a higher nursing visit frequency. For seniors living alone, OPAT can still work, but the nursing schedule and emergency contact plan need to be more thorough.

Medi-Cal and home infusion

Medi-Cal covers home infusion services for members through Medi-Cal-enrolled providers. Most home infusion for dual-eligible California seniors flows through Medicare as primary (the Home Infusion Therapy benefit plus DME), with Medi-Cal as secondary picking up cost-sharing. For Medi-Cal-only members, the managed-care plan coordinates home infusion through its contracted suppliers, with prior authorization typically required for the drug and pump.

Medi-Cal Rx, the carve-out pharmacy program administered by Magellan, handles certain outpatient pharmacy benefits for Medi-Cal members. Home infusion drugs delivered via external pump generally fall under the medical benefit rather than Medi-Cal Rx, but the boundary can be plan-specific.

How to start, step by step

If the senior is in the hospital and discharge with IV therapy is being planned: ask the discharge planner specifically about a home infusion referral and which supplier is being used.
Confirm the IV access (PICC line, midline) is placed before discharge. Replacing it from home is harder.
The home infusion supplier contacts the family within 24 hours of referral. The first delivery and nurse visit typically happens within 24 to 48 hours of discharge.
Ask the supplier’s clinical team for the teaching materials and the after-hours phone number. Keep both visible at home.
Confirm the lab monitoring plan: what labs, drawn by whom, sent to whom, reviewed by whom, on what schedule.
For Medicare Advantage members: confirm the supplier is in network and the prior authorization is in place before discharge to avoid delays.
For Medi-Cal members: the managed-care plan’s case manager can help coordinate the home infusion supplier and any related benefits.

Common misconceptions to clear up

“IV antibiotics require a nursing home.” Not since the Home Infusion Therapy benefit was established. Most clinically stable seniors with appropriate IV access can complete long-course IV antibiotics at home.

“Medicare won’t pay for IVIG at home.” IVIG is one of the most common home infusion therapies covered under the Part B benefit when prescribed for a covered indication.

“The drug is on Part D.” Most pump-administered IV drugs are not Part D. They are covered as Part B DME with Home Infusion Therapy professional services on infusion days. Sending the prescription to a Part D pharmacy will often produce confusion and delay.

“Home infusion is too risky for elderly patients.” Risk depends on candidate selection, access type, caregiver support, and supplier quality, not age. With those in place, home OPAT outcomes match or exceed inpatient and facility-based care for appropriate indications.

Related services and next steps

This guide explains coverage and eligibility, not medical advice. Talk to a licensed clinician about care decisions. California Care Compass does not place referrals on Services & Treatments pages.

Home IV infusion for California seniors: Medicare’s Home Infusion Therapy benefit, in practice.